Many inflammatory diseases of the intestinal wall are caused or influenced by changes in the intestinal microbiota and/or an impaired interaction between the intestinal microbiota and the intestines. Such intestinal inflammations occur in humans, e.g., inflammatory bowel diseases (IBD), such as Crohn's disease or ulcerative colitis, but also in other mammals (e.g., chronic idiopathic colitis in dogs). These diseases are based on complex immunological processes which are not fully understood. However, changes in, and impaired interactions of, the intestinal microbiota can also be causative factors in a number of other diseases. Examples include atopic diseases, such as atopic eczema, allergic conditions or asthma (see e.g., Bisgaard et al. 2011, J. Allergy Clin. Immunol. 128:646; Iebba et al. 2011, Dig. Dis. 29:531; Abrahamsson et al. 2012, J. Allergy Clin. Immunol. 129:434; Candela et al. 2012, BMC Microbiol. 12:95; Olszak et al. 2012, Science 336:489), as well as metabolic diseases with an inflammatory component, such as arteriosclerosis with resulting coronary heart diseases, adiposity or diabetes (Ott et al. 2006, Circulation 113:929; Koren et al. 2011, PNAS 108 Suppl 1:4592; for reviews see Caesar et al. 2010, J. Intern. Med. 268:320; and Vrise et al. 2010, Diabetologia 53:606).
Although the relationship between the intestinal microbiota and various diseases is known, it has not been understood how to influence the microbiota in a way that would positively impact associated diseases.
Nicotinic acid (niacin, vitamin B3), nicotinamide (nicotinic acid amide) and/or L-tryptophan have been used for the therapy of niacin deficiency diseases (e.g., pellagra) for decades. It is known that pellagra may be accompanied by intestinal inflammation, which is ameliorated after niacin administration, where the therapeutic principle is the elimination of the vitamin deficiency causing the intestinal inflammation (Segal et al. 1986, Int. J. Colorectal Dis. 1:238; and Clayton et al. 1991, Eur. J. Pediatr. 150:498).
It is also known that nicotinic acid has a health-promoting effect on cholesterol lipoproteins in the blood (HDL/LDL ratio and size of the LDL vesicles; Wahlberg et al. 1990, J. Intern. Med. 228:151; Seed et al. 1993, Atherosclerosis 101:61; Elam et al. 2000, JAMA 284: 1263; McKenney et al. 2001, Am. J. Cardiol. 88:270).